To a flask containing 32.7 gm (0.15 mole) of diphenyl disulfide dissolved in 100 ml of dichloromethane containing 3 ml of pyridine is slowly dropwise added at room temperature 20.3 gm (0.15 mole) of freshly distilled sulfuryl chloride. After completion of the addition, the solution is stirred for an additional hour, concentrated under reduced pressure (12 mm Hg) at 25°C, and the residue distilled to afford 33 gm (76%), b.p. 49°C (4 mm Hg), of a dark red liquid.
